1. Field of the Invention
The present invention is concerned with microbicidal/microbistatic compositions for industrial use which comprise 4,5-dichloro-1,2-dithiol-3-one and 1,2-benzisothiazolin-3-one and with a method of killing and/or inhibiting microbes by using these compositions.
2. Description of the Prior Art
4,5-Dichloro-1,2-dithiol-3-one which has the chemical formula: ##STR1## is known to have a strong microbicidal/microbistatic activity, especially against Gram negative bacteria (cf. Japanese Patent Publication No. 14294/1977).
On the other hand, 1,2-benzisothiazolin-3-one having the chemical formula of ##STR2## is also known to show a good microbicidal/microbistatic activity, especially against Gram positive bacteria (cf. Japanese Patent Publication No. 7999/1963).
Microbicidal/microbistatic compositions comprising 4,5-dichloro-1,2-dithiol-3-one and a haloacetic acid ester are also known (cf. published British patent specification No. 2,052,989).
The invention is based on the discovery that when the above-mentioned two types of active ingredients are used for various industrial purposes requiring a microbicidal/microbistatic treatment (especially in papermaking process water), they produce a synergistically potentiated microbicidal/microbistatic activity, while retaining their respective microbicidal spectra, and also sustain their activities.